Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06520

Behavioral responses to quick 1 s Eb pulses are dependent on temporal odor dynamics in the behavioral chamber. A, Velocity of flies during and after 1 s Eb pulses is dependent on initial position within the olfactory arena at initiation of the odor pulse. Control flies expressing PDF-RNAi in OR22a-expressing neurons exhibit strong avoidance only to 1:1 Eb and only when initial position in the arena is ≤4 cm from the odor port. Mean ± SEM; n = 116–172 total flies per genotype and concentration assayed in at least 10 independent experiments. Statistical analysis: two-way ANOVA with Bonferroni post hoc test, *p < 0.05. B, Behavioral responses of control flies (initial position to port <5 cm) to 1 s Eb pulses of gas-phase dilutions, as indicated in A. Mean ± SEM. C, D, Mean PID recordings (n = 5) in the behavioral chamber showing odor dynamics of 1 s odor pulses of 1:5 (C) and 1:1 (D) that vary dependent on the distance to the odor port. E, F, Tau represents the time that the odor stimulus takes to reach 36.8% of its peak value. For 1:5 (E) and 1:1 (F), tau drastically increases after a distance of 3–4 cm from the odor port, indicating that flies within 3 cm from the odor port experience a fast increase and decrease in odor intensity, while flies that are >3 cm away from the odor port experience more gradual changes in odor intensity. Mean ± SEM. n = 5.